Kit for constructing ladders and the like



1969 L. A. CORMIER 3,476,211

KIT FOR CONSTRUCTING LADDERS AND THE LIKE Filed Dec. 196'? 4 Sheets-Sheet 1 INVENTOR.

Louis A. Cormier ATTORN Y Nov. 4, 1969 A. CORMIER 3,476,211

KIT FOR CONSTRUCTING LADDERS AND THE LIKE Filed Dec. 4, 196" 4 Sheets-Sheet 2 Nov. 4, 1969 L. A. CORMIER 3,476,211

KIT FOR CONSTRUCTING LADDERS AND THE LIKE Filed Dec. 4, 1967 i K 4 Sheets-Sheet .S

Nov. 4, 1969 L. A. CORMIER 3,476,211

KIT FOR CONSTRUCTING LADDERS AND THE LIKE Filed Dec. 4. 196'. 4 Sheets-Sheet 4 United States Patent O US. Cl. 18222 Claims ABSTRACT OF THE DISCLOSURE The kit comprehends the provision of a number of standard parts and elements adapted to be fitted together in various ways to provide a ladder or step ladder or saw horse or work bench and the like.

BACKGROUND OF THE INVENTION In the modern do-it-yourself age of home decorators and indeed for many construction projects, the use of various kinds of ladders, racks, work benches, saw horses etc. is essential if the work is to be done in the safest and most elficient manner. All varieties of unitary structures of this kind can be purchased, each unit having its particular shape and structure to perform a given function. To provide and maintain a complete set of all such units is out of the question for most do-it-yourselfers and even for many smaller contractors. It is the particular purpose of my invention to provide a set of modular elements that can be assembled to form a given unit and then reassembled with other fittings to form another kind of unit. My invention thus provides a set of parts most of which are identical in size and construction which may be fitted together with other parts to make a number of differently shaped construction aids.

BRIEF DESCRIPTION OF INVENTION The various pieces of construction equipment such as ladders, benches, etc. that may be made with my kit may be disassembled for convenient storage in a minimum of space. I provide a set of standard straight elements, together with an assortment of angular fixtures that may be easily assembled together to provide side frames, steps, and various supporting means such as are invariably needed at construction projects. The elements are all designed to have standard mating joints and only a few kinds of angular elements are needed to join the various planar assemblies together in any number of different patterns whereby to form a wide variety of different kinds of construction equipment, all of the details of which will appear more fully below.

IN THE DRAWINGS FIG. 1 is a perspective view of a step ladder assembled from the elements of my kit;

FIG. 2 is a side elevation showing the other side of the step ladder shown in FIG. 1;

FIG. 3 is a front elevation of a planar unit that constitutes a straight ladder forming one side of the step ladder shown in FIG. 1;

FIG. 4 is a perspective view of a longer straight ladder formed by adding the two planar units or sides of the step ladder together;

FIG. 5 is a view taken on line VV of FIG. 2;

FIG. 6 is a view taken on line VIVI of FIG. 2;

FIG. 7 is a view taken on line VII-VII of FIG. 6;

FIG. 8 is a detail exploded view of a stretcher element of my kit;

FIG. 9 is a detail view partly broken away showing a modular side element of my kit connected to a second such element;

3,475,211 Patented Nov. 4, I969 FIG. 10 is a detail showing of a modular strut or connector element of my kit;

FIG. 11 shows the use of the parts to form a saw horse;

FIG. 12 shows the use of the parts to form a hand truck;

FIG. 13 is a perspective view of an alternative form of the step; and

FIG. 14 is an end view of the step.

DETAILED DESCRIPTION OF THE INVENTION My kit basically includes only a few elements that may be interfitted to form a number of differently shaped pieces of construction gear. Sturdy side elements are designed to be joined together to reach to any reasonable height. Stretcher elements are designed to join the side elements together and means are provided to simultaneously lock the assembled unit into a rigid unitary assembly. These simple basic elements of my kit are also adapted to cooperate with right angle, or acute angle joint elements to make tables or step ladders or other pieces of equipment out of the planar unitary assemblies of the basic kit. A set of braces or looking strips complete the kit.

Referring to FIG. 1, a typical unit that may be constructed with my kit is shown. This step ladder has four legs indicated by arrows 10, 11, 12 and 13 each of which is made up of a plurality of tubular element 14 as shown in FIG. 9. Each element 14 is adapted to have a dowel 15 integral with one end thereof, the dowel being tightly fitted into the tubular portion of the element 14, with the outwardly extending end of the dowel being adapted to fit neatly into the open or socket end of the next tubular element 14 to be fitted thereto. Each element 14 is provided with a pair of transversely extending apertures 16 and 17 which pass entirely through the element from side to side. In the step ladder shown in FIG. 1, the legs 10 and 11 and legs 12 and 13 are each joined together in their respective single planes by a plurality of stretcher elements 20 like that shown in FIG. 8.

The stretcher elements are all of the same length and are provided with threaded pins 21 extending outwardly from each end. The pins 21 are designed to fit snugly in apertures 16 of the side elements 14 so that these stretcher and side elements may be interfitted and assembled together at right angles to each other to form a rigid planar construction. In order to hold a number of the side elements and stretcher elements assembled together, locking strips 25 are provided. The locking strips are designed to fit closely against the sides of the side elements 14 and extend from aperture 16 in one element to aperture 17 in the next adjacent side element 14. The pins 21 of the stretcher elements extend through the apertures 16 and 17 to have the apertured ends of the locking strips 25 fitted over them and engaged tightly against the side elements by wing nuts 26 or the like as shown in FIG. 3. It will be noted that each of the locking strips 25 bridges the joint between the two side elements to form an integral planar structure.

The step ladder shown in FIG. 1 is assembled by joining two side elements 14 together to form each of the legs 10, 11, 12 and 13. The stretcher elements 20 are inserted to form the pair of front and back planar structures that are assembled together to be angularly related to each other as best shown in FIG. 2. The legs 10 and 12 and legs 11 and 13 are shown joined at the top by angular joint element 29 having suitable slip fit connection means for rigidly connecting the ends of the respective side legs together at their top ends.

The step ladder shown in FIGS. 1 and 2 is completed by tieing the front and rear planar structures together with horizontal side braces 30 of various lengths. The braces 34) have apertured ends and are adapted to be fitted onto the extending ends of pins 21 to abut side elements 14, as best seen in FIG. 5. The braces 30 join the front and rear planar structures together to form a rigid triangular pattern to stiffen the completed structure. The braces are horizontally arranged as best seen in FIG. 2.

In order to make the step ladder more serviceable, treat or step elements 31 may be fitted to each of the stretcher elements 20 of one or both of the angularly disposed planar elements. Each of the tread means includes a horizontally disposed stepping surface 32 that may be notched at each end and supported on the top surface of stretcher 20 as best shown in FIGS. 2 and 7. It may be stiffened by tabs 33 and 34 integral therewith. With such a construction, after the basic step ladder structure has been assembled, the step element 31 may be simply fitted diagonally through the opening between the side elements 14 and stretcher elements 20 by being turned at an angle, with tabs 33 and 34 pointing down. The step is thus firmly supported on stretcher 20 against rocking in any direction when a person steps on it. The notches on the step pad that interfit around side elements 14 prevent the step from sliding horizontally, when the step ladder is in use.

The two angularly disposed planar elements shown in FIGS. 1 and 2 which form the fornt and back of the step ladder can be joined end to end as shown in FIG. 4 to form a straight ladder. With either the step ladder or straight ladder, suitable hard rubber pads 40 are in the hollow ends of the lower sections to form foot pads for the ladder structures.

As is evident in FIG. 9, the important element of the apparatus is the element 14. It is composed of a thinwalled tube of metal, such as aluminum or plastic; this permits the element to resist weathering and gives it toughness. The dowel is inserted tightly in the tube and extends almost its entire length; the dowel is formed of a stilt, inexpensive material, such as fiberglass reinforced plastic or wood, which will lend stiffness and strength to the element.

In other forms of my invention, angular joints formed at right angles but otherwise similar to the angle joints 29 can be used to join the basic planar structures together to form tables, benches or stands having flat working surfaces. With the acutely-turned angular joints 29, a saw horse can be constructured. Due to the modular design of the elements 14 forming the side pieces and the stretchers together with the locking strips and braces 30, all of the above-described combinations can be assembled from the five or so basic elements forming my kit. For instance, the parts can be assembled, as shown in FIG. 11 to form a saw horse. Another variation is the hand truck shown in FIG. 12, which truck may be used in moving furniture around the house.

With such a group of elements, it is readily apparent that they may be stored in a minimum of space in their disassembled condition. Yet when needed, a step ladder or long straight ladder or a work bench, rack or stand, suitably braced, may be easily assembled on the job to facilitate working on all sorts of construction projects.

The elements shown in the drawings have been formed from tubular metal parts. It is obvious that they may be made from square or triangular, or other shape of stock. It is also suggested that a cotter pin connection or other quickly assembled connector means can be substituted for the threaded pin 21 and wing nut 26.

FIGS. 13 and 14 show a way in which a step 40 can be formed as one integral piece from cast aluminum or the like. It is made up of a rectangular mai plate 41 whose central upper surface is formed with a non-slip configuration 42. At the opposite ends, it is provided with bearing members 43 and 44. These members are in the form of semi-tubular elements and are inclined to the plane of the main plate at an angle commensurate with the ladder angle. They are also provided with laterallyextending apertures 45 by which they can be attached to the ladder by making use of bores in the ladder and cotter pins.

The above description covers the preferred embodiment of my invention. Modifications thereof may occur to those skilled i the art which will fall within the scope of the following claims.

I claim:

1. A kit from which planar structural units may be assembled, comprising a plurality of elongated side elements, said elements have one end provided with a socket, and each of said elements having dowels fixed therein and extending from the other end thereof, said extending dowel end being adapted to interfit with the socket end of another elongated side element, said side elements having a plurality of apertures disposed transversely thereof, and elongated stretcher elements for assembly with said elongated side elements, said stretcher elements having pins extending from both the ends thereof, said pins being adapted to be fixed into said apertures and locked integral with said side elements, whereby at least one pair of side elements can be assembled with at least one pair of stretcher elements to form a planar structural unit, a plurality of such planar units being adapted to be assembled together, including elongated locking strips for engaging the pins of adjacent stretcher elements when they are disposed between the side elements, said locking strips fitting along the edges of said side elements and being of a length to bridge the joint between two side elements when they are doweled together in end to end relation whereby an elongated composite rigid palnar structure is formed from a plurality of planar units.

2. The structure of claim 1 in combination with a plurality of rigid angular joint elements, said angular elements having interfitting connections with the side elements of said planar units whereby to form shaped pieces of construction equipment.

3. The structure of claim 1 wherein the angular joint elements are formed to have an acute angle and said interfitted planar units are disposed at angular relation to each other, side brace means joining the side elements of said planar units, said braces being supported on the pins of said stretcher elements, whereby to form a step ladder.

4. The structure of claim 3 wherein a plurality of step elements are provided, each of said step elements being adapted to be supported on one of said stretcher elements respectively, said step elements each having hook means to engage both above and below said side brace means to hold each of said step elements fixed on its respective stretcher element.

5. The structure of claim 4 wherein said step elements are longer than its respective supporting stretcher element, and said step element being notched to permit it to fit onto the stretcher element with the notch fitting around he side element of the planar unit.

References Cited UNITED STATES PATENTS 45,430 12/1864 Olds 18227 2,103,603 12/1937 Voight 182120 2,528,317 10/1950 Newman 18212O 2,992,697 7/ 1961 Klages 182-216 3,371,458 3/1968 Sturgill 182178 FOREIGN PATENTS 119,247 1 1/ 1944 Australia. 850,791 9/ 1952 Germany. 167,520 4/ 1956 Australia.

REINALDO P. MACHADO, Primary Examiner US. Cl. X.R 

